Thin films of doped TCO for PN junction applications

Transparent conductive oxides (TCOs) combining optical transparency and electrical conductivity are essential for thin-film photovoltaic technologies. This work explores the synthesis of undoped and doped (Li V Gd) ZnO thin films by chemical spray pyrolysis with a view to their integration into PN junctions. Atom probe tomography (APT) revealed a homogeneous Li distribution. Raman FTIR SEM EDX and XPS analyses confirm the structure and composition of the films. Vanadium-doped films show a wurtzite structure good transparency (400-1200 nm) a bandgap of 3.18-3.26 eV and improved microhardness. Gadolinium doping modifies the morphology and maintains an optical transmission of 60-80% with a bandgap of 3.24-3.26 eV. Finally the n-ZnO/p-Si heterojunctions produced show promising performances confirming the interest of the layers for photovoltaic and optoelectronic applications.